fix: preserve MCP tools when "default" tools preset is active without explicit tools list

When the "default" preset was used alone (no explicit --tools list),
_apply_tool_filters built an allow_set containing only built-in tool
names, silently stripping all mcp__ prefixed tools. This caused SDK
agents using ToolsPreset to lose access to their registered MCP tools.

Return the full tool list early when preset is "default" and no
explicit tools_list is provided, matching the upstream behaviour where
"default" resolves to the complete set of enabled tools.

Author: FrostMiKu

ripperdoc/protocol/stdio/handler_config.py

@@ -102,10 +102,14 @@ def _apply_tool_filters(
         if tools_list is not None:
             allow_set = set(tools_list)
 
-        # "default" preset independently adds all built-in tools.
+        # "default" preset adds all built-in tools to the allow set.
+        # When no explicit tools_list is provided, preserve all registered
+        # tools (built-in + MCP) so that MCP servers aren't silently stripped.
         if preset == "default":
+            if allow_set is None:
+                return tools
             builtin_names = {name for name in tool_names if not name.startswith("mcp__")}
-            allow_set = builtin_names if allow_set is None else allow_set | builtin_names
+            allow_set = allow_set | builtin_names
 
         if allow_set is None:
             return tools

ripperdoc/utils/mcp.py

@@ -1488,7 +1488,7 @@ def format_mcp_instructions(servers: List[McpServerInfo]) -> str:
     lines: List[str] = []
     if connected_count > 0:
         lines.append(
-            "Connected MCP servers are available. Call tools via CallMcpTool by specifying server, tool, and arguments."
+            "Connected MCP servers are available."
         )
     else:
         lines.append(